rollup.config.js

import vue from 'rollup-plugin-vue'
import buble from 'rollup-plugin-buble'
import commonjs from 'rollup-plugin-commonjs'
import replace from 'rollup-plugin-replace'
import { terser } from 'rollup-plugin-terser'
import resolve from 'rollup-plugin-node-resolve'
import css from 'rollup-plugin-css-only'
import minimist from 'minimist'
import pkg from './package.json'

const argv = minimist(process.argv.slice(2))

const baseConfig = {
  input: 'src/index.js',
  plugins: {
    preVue: [
      replace({
        'process.env.NODE_ENV': JSON.stringify('production')
      }),
      commonjs()
    ],
    vue: {
      css: true,
      template: {
        isProduction: true
      }
    },
    postVue: [
      buble({
        transforms: {
          dangerousForOf: true
        }
      })
    ]
  }
}

// Customize configs for individual targets
const buildFormats = []
if (!argv.format || argv.format === 'es') {
  const esConfig = {
    ...baseConfig,
    output: {
      file: pkg.module,
      format: 'esm',
      exports: 'named',
      sourcemap: true
    },
    plugins: [
      ...baseConfig.plugins.preVue,
      css({
        output: pkg.style
      }),
      vue({
        ...baseConfig.plugins.vue,
        css: false
      }),
      ...baseConfig.plugins.postVue,
      terser({
        output: {
          ecma: 6
        }
      }),
      resolve()
    ]
  }
  buildFormats.push(esConfig)
}

if (!argv.format || argv.format === 'cjs') {
  const umdConfig = {
    ...baseConfig,
    output: {
      compact: true,
      file: pkg.main,
      format: 'cjs',
      name: 'VueLazyLoad',
      exports: 'named',
      sourcemap: true
    },
    plugins: [
      ...baseConfig.plugins.preVue,
      css({
        output: pkg.style
      }),
      vue({
        ...baseConfig.plugins.vue,
        template: {
          ...baseConfig.plugins.vue.template,
          optimizeSSR: true
        },
        css: false
      }),
      ...baseConfig.plugins.postVue,
      resolve()
    ]
  }
  buildFormats.push(umdConfig)
}

if (!argv.format || argv.format === 'iife') {
  const unpkgConfig = {
    ...baseConfig,
    output: {
      compact: true,
      file: pkg.unpkg,
      format: 'iife',
      name: 'VueLazyLoad',
      exports: 'named',
      sourcemap: true
    },
    plugins: [
      ...baseConfig.plugins.preVue,
      vue(baseConfig.plugins.vue),
      ...baseConfig.plugins.postVue,
      terser({
        output: {
          ecma: 5
        }
      }),
      resolve()
    ]
  }
  buildFormats.push(unpkgConfig)
}

// Export config
export default buildFormats